For example, a large number of computers (server devices) or the like have been heretofore disposed in a server room or the like in a data center or an enterprise. There is a possibility that heat generated in the larger number of server devices may increase the room temperature of such a server room, thereby causing out of control or breakdown of any one of the server devices. Therefore, the server room uses an air conditioning system for keeping the overall temperature of the room constant. Such an air conditioning system is operated almost full-time so that it is operated even in winter.
In the background-art air conditioning system for such a server room or the like, low-temperature air (cold air) blown out from air conditioning devices flows into the server room while contacting with server devices in server racks to cool the server devices in order to attain stability of the room temperature of the server room. There is used a circulation system in which air (warm air) consequently warmed up by heat of the server devices is returned from the server room into the air conditioning devices and cooled by the air conditioning devices so that the cooled air is blown out again as the cold air and fed into the server room again.
An air conditioning device using outdoor air for generating the cold air has been known. That is, there has been known an air conditioning device utilizing outdoor air in which the warm air (air returned from the server room) and outdoor air are made to pass through a heat exchanger to perform heat exchange between the warm air and the outdoor air so that the warm air is cooled and changed into cold air by the outdoor air.
A background-art technique described in Patent Literature 1 has been known.
For example, a configuration shown in FIGS. 1(A) and 1(B) has been disclosed in Patent Literature 1. That is, first, one cabinet group is formed in such a manner that a plurality of cabinets is arranged in a single horizontal row in an X direction. Such cabinet groups are provided in a plurality of rows. A shielding unit including first and second vertical curtain portions, a horizontal curtain portion and an end vertical curtain portion, is attached to cable racks corresponding to two rows of cabinet groups opposite to each other. The shielding unit forms a shielded space (cold aisle) for cooling in a passage where the two rows of cabinet groups face each other. For example, these curtain portions are made of vinyl chloride sheets, panels, or the like.
Patent Literature 1: JP-A-2009-36490